You forgot one major reason to upgrade from a PSR2000 to a Tyros Scott: double the polyphony!!!

If you can afford the Tyros, the choice between that and any PSR is a no-brainer (eBay will be loaded with used PSR's I predict). Undoubtedly the Tyros is a worthy succesor to the PSR line... now I'm looking forward to see what will replace the 9000 Pro in turn.